Without limiting the scope of the invention, its background is described in connection with model toys.
One such toy is taught in U.S. Pat. Nos. 9,308,461 and 8,500,508, issued to Yamada, et al., entitled “Transformable toy”, teach a toy with an exterior structure that is constructed to transform from a rollable first shape to a second shape. An interior structure inside the exterior structure is endowed with a magnetic body that moves by way of a magnetic force that acts from the exterior of the toy, an interior locking portion that moves simultaneously with the movement of this magnetic body, and a biasing member that effects a force which moves or turns this interior locking portion in a particular direction. According to this invention, if the magnetic force does not act from the exterior of the toy, the first shape of the exterior structure maintained. In the event that a magnetic force has acted from the exterior of the said toy, the exterior structure transforms from the first shape to the second shape.
Another such toy is taught in U.S. Pat. No. 7,166,047, issued to May, et al., entitled, “Toy ball”, which teaches a toy ball that is formed from two shells and a pair of lock mechanisms. During construction, the shells, which may be hemispherical, are mated together and then the lock mechanisms are secured to the shells to form a substantially smooth-surfaced sphere, wherein the lock mechanisms provide a redundant locking feature to hold the two shells together to form the toy ball.
Finally, U.S. Pat. No. 5,409,414, issued to Sheang, and entitled “Toy sphere” teaches a toy sphere that includes an annular member provided with a circular groove at both sides, a plurality of internal gear teeth at an inner surface, and two opposite eccentric pins at an outer surface, a power seat threadedly engaged with the internal gear teeth of the annular member and having a motor electrically connected with batteries, an upper hemispherical housing having internal threads, a lower hemispherical housing having external threads engageable with the internal threads of the upper hemispherical and having two aligned holes engaged with the two opposite eccentric pins of the annular member.